DAVIE, Fla. (AP) — Suspended Miami Dolphins guard Richie Incognito sent text messages to teammate Jonathan Martin that were racist and threatening, two people familiar with the situation said Monday.

The people spoke to The Associated Press on condition of anonymity because the Dolphins and NFL haven't disclosed the nature of the misconduct that led to Incognito's suspension.

Martin, a tackle, remained absent from practice Monday one week after he suddenly left the team. Also missing was Incognito, suspended indefinitely late Sunday by Miami for his treatment of Martin.

The team and NFL continued their investigation into allegations by Martin's representatives that he was bullied. The NFL Players Association also planned to look into the matter.

The 319-pound Incognito, a ninth-year pro, is white. The 312-pound Martin, who is in his second NFL season, is black.

It's unclear whether Dolphins coaches and management had any inkling of harassment between players before Martin left the team. Recent rumblings of locker-room dissension have also included complaints by young players that they're pressured to pay more than their share when team members socialize together.

Before being suspended, Incognito posted several tweets saying he wanted his name cleared.

"Three things cannot be long hidden: the sun, the moon, and the truth," Incognito tweeted, quoting Buddha.

Agents for the two players didn't respond Monday to requests for comment. Martin is with his family in Los Angeles for counseling.

Incognito has long had a reputation as one of the NFL's dirtiest players. During his first four years, he led the league in penalties for unnecessary roughness, and the St. Louis Rams got fed up with his undisciplined play and released him during the 2009 season.

"There's certain people out there who are just punks, and he wants to be that kind of guy," former Seahawks and Lions defensive end Lawrence Jackson said Monday. "But because he's a lineman, he gets away with a lot of stuff that people don't see. ... Incognito is way worse than anybody I ever played against."

However, there have been fewer such complaints since Incognito joined the Dolphins in 2010.

Last year he was voted by the league's players into the Pro Bowl for the first time. He was the co-winner of the Dolphins' Good Guy Award, given to the team's most cooperative player by the local media. He also won frequent praise from Dolphins coaches for his leadership, and this year he was voted by teammates to serve as a member of the Dolphins' player council.

At Nebraska, Incognito's career was cut short when he was suspended in 2004 before his junior season following a locker room altercation with a teammate. He also ran into problems with the law while with the Cornhuskers, and they said he repeatedly violated team rules.

Martin protected Andrew Luck's blind side at Stanford before joining Miami as a second-round draft pick in 2012. He has been a starter since the beginning of his rookie season, but has struggled while dividing his time between left and right tackle.

For the first six games this year, Incognito and Martin were the two players protecting Ryan Tannehill's blind side, which may help explain his league-high 35 sacks.